A. Field of the Invention
The present invention relates to implements and apparatus for manually transporting and manipulating relatively large, heavy, and generally flat articles such as tables and construction materials in the form of large flat sheets of plywood, plasterboard, or the like. More particularly, the invention relates to a transport system for articles of the character described, comprising a leveraging dolly for lifting and transporting individual tables or other such articles, and a racking cart which functions in combination with the leveraging dolly to receive and transport a quantity of tables or tabular construction materials.
B. Description of Background Art
Tables provided with folding legs are widely used during conferences, seminars and similar events held at schools, banquet halls, hotels, churches and a wide variety of other such venues. Since the location, layout and number of such tables required for a particular event are all variable, it is customary to transport such tables with the legs folded-up from a storage area to a hall or other event site, unfold the legs and place the tables at desired locations of the site. Upon completion of an event, the tables must be folded up, lifted onto a cart, and transported to a storage area or other location.
The tasks of transporting, unfolding, deploying, and re-folding or "knocking down" tables described above are generally performed by humans without the assistance of machines, and thus require a substantial expenditure of physical labor. Typical tables of the type used at conferences, churches and other such venues are six to eight feet long, 24 to 36 inches wide, and may weight 40 to 90 pounds or more. Round tables for similar applications may be five feet or more in diameter and are similarly heavy. Thus, it can be readily appreciated that such tables are ergonomically awkward for a person to handle, and that lifting, folding and unfolding such tables can and does frequently result in muscle or back strain, or more serious injuries. In many churches, in particular, older volunteer persons are frequently called upon to undertake the task of transporting, setting up and taking down folding tables, with even greater risk of straining muscles in the back or other parts of the body. In fact, the amount of force which must be exerted by an individual to tilt a folding table into an upright position preparatory to folding the table legs parallel to the table top for convenient transporting of the table frequently requires the exertion of physical strength beyond that which an elderly person may be reasonably expected to be capable of.
In addition to the ergonomic problems in manipulating tables alluded to above, present methods of manipulating and transporting tables often result in damage to the table; caused for example, by impact of a table corner with a floor or wall, or misuse of a table appendage as an unintended handle.
The handling of certain building materials widely used in the construction industry is beset with problems similar to those associated with the deployment of folding tables, as described above. Thus, many residential, commercial and industrial building construction projects utilize a variety of large, flat heavy structural or ornamental materials such as plywood panels, plasterboard sheets referred to as "dry wall" or "sheetrock," and the like. Such tabular construction materials are typically delivered to a construction site and deposited there in a flat stack. From there, individual sheets are carried to an installation location such as on a wall or floor, and secured in place. Typical construction sheet material is manufactured and supplied as 4 ft. by 8 ft. sheets weighing up to 100 pounds or more. Therefore, moving such sheets requires a great deal of expended energy, and at present is usually assisted only by such contrivances as a simple wheeled cart.
In view of the foregoing problems associated with the transportation and disposition or relatively heavy and cumbersome articles such as folding conference tables and tabular construction materials such as plywood sheets, plasterboard sheets, and the like, the present invention was conceived of.